The invention, which is sought to be protected in this CIP application, relates generally to hazardous wastes, and, more specifically, to vitrification thereof for long term storage.
U.S. patent application Ser. No. 09/350,194 and the disclosure of U.S. Pat. No. 5,678,237, which provides a device and method of in-situ vitrification of waste materials in a disposable canister, are hereby incorporated herein by reference. The disposable canister is a module comprising an inner container, an outer container, and insulation therebetween. The outer container serves as the traditional disposal container typically made of steel, which is thermally insulated from an inner container, typically of made of graphite. The inner container serves as a crucible to melt a waste/frit mixture and contain a molten vitrified product. The inner container is typically made of graphite and is typically heated by induction.
The frit material in the traditional process is granulated, that is, it is in the form of fine granules, typically 100 mesh or smaller. The invention sought to be protected is a method using solid chunks of material having a minimum dimension through the centroid of the chunk of about one-eighth of an inch.
The Advanced Vitrification System Frit (AVSF) invention is an improvement on the method for vitrification of wastes in a final disposal canister. The invention will help to improve and control product glass quality, shorten the required melt period, maximize glass fill fraction in the canister, control time and temperature profiles for a melt, and maximize heat transfer rate from a heated inner container into the interior of the melt. In the process, chunks of frit are combined with waste and then added to the disposable canister. The waste and frit are then heated to melt the frit and waste. The melted mixture is then cooled to form a vitrified product in the module.